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Study Questions and References

Study Questions
and References

Cows walking to the barn.

Study Questions

1. Ergot toxicity causes a number of physiological responses in animals. Ergotism is caused by the ingestion of ergot alkaloids that are produced by endophytic fungi that live in the seed heads of various grains. One response vasoconstrition of peripheral blood vessles, and another response is a severe decrease in prolactin secretion from the pituitary. Administration of bromocryptine (also called CB-154), a synthetic ergot alkaloid that is not vasoconstricitve, is often used experimentally (or sometimes medically in humans) to reduce prolactin secretion from the pituitary. What would you expect the response in milk production in the lactating female of the following species to be after administration of bromocryptine:

  • rabbit
  • rat
  • human
  • cow
  • sheep
  • pig

In each case, how would milk production be estimated?

2. In a cow, milk contained in the cisterns and cisternal ducts (called cisternal milk) contains FIL, but because it is not localized in the alveolar lumen, then the presence of milk in the cisterns does not inhibit further milk secretion. How would the presence of large cisternal volumes in a mammary gland, such as in a cow, affect the production of milk compared with a sow that has very little cisternal volume? How would the presence of large cisternal volumes in a mammary gland, such as in a cow, affect the requirement for frequent milkings compared with a sow that has very little cisternal volume?

Udder cut in cross-section showing cisterns and cisternal ducts.
Cisterns and cisternal ducts are indicated in red. Remember this image from the Mammary Structure Module, Internal Anatomy?

3. You might look at the cow's mammary gland as containing three portions of milk. A) Cisternal milk that includes milk that was left over from the last milking (last milking's residual milk) and the initial milk synthesized by the gland after a milking, B) alveolar milk that is the milk ejected in response to normal milking and includes milk secreted after the last milking, and C) residual milk that is not removed by a normal milking. Below is a group of cows. How would you go about collecting each of the three milk fractions from each cow?

A group of cows standing by a barn.



Akers RM (1990) Lactation physiology: a ruminant animal perspective. Protoplasma 159:96-111.

Tucker HA (1994) Lactation and its hormonal control. Ch. 57, In: The Physiology of Reproduction, 2nd edition, Eds. E. Knobil, J. Neill, et al. Raven Press, Ltd., New York. p. 1065.

Wilde CJ, Hurley WL 1996 Animal models for the study of milk secretion. J. Mammmary Gland Biol. Neoplasia 1:123-134.

Wilde CJ, Knight CH (1989) Metabolic adaptations in mammary gland during the declining phase of lactation. J Dairy Sci 72:1679-1692

Photoperiod and Milk Production

Bilodeau, P.P., D. Peticlerc, N. St. Pierre, et al. 1989. Effect of photoperiod and pair-feeding on lactation of cows fed corn or barley grain in total mixed rations. J. Dairy Sci. 72:2999-3005.

*Dahl, G.E., B.A. Buchanan, and H.A. Tucker. 2000. Photoperiodic effects on dairy cattle: a review. J. Dairy Sci. 83:885-893.

Dahl, G.E., T.H. Elsasser, A.V. Capuco, et al. 1997. Effects of a long daily photoperiod on milk yield and circulating concentrations of insulin-like growth factor-I. J. Dairy Sci. 80:2784-2789.

Evans, N.M., and R.R. Hacker. 1989. Effect of chronobiological manipulation of lactation in the dairy cow. J. Dairy Sci. 72:2921-2927.

Miller, A.R.E., R.A. Erdman, L.W. Douglass, et al. 2000. Effects of photoperiodic manipulation during the dry period of dairy cows. J. Dairy Sci. 83:962-967.

Peters, R.R., L.T. Chapin, R.S. Emery, et al. 1981. Milk yield, feed intake, prolactin, growth hormone, and glucocorticoid response of cows to supplemented light. J. Dairy Sci. 64:1671-1678.

Peters, R.R., L.T. Chapin, K.B. Leining, et al. 1978. Supplemental lighting stimulates growth and lactation in cattle. Science 199:911-912.

Peticlerc, D., C.M. Vinet, G. Roy, et al. 1998. Prepartum photoperiod and melatonin feeding on milk production and prolactin concentrations of dairy heifers and cows. J. Dairy Sci. 81(suppl.1):251.

Stanisiewski, E.P., R.W. Mellenberger, C.R. Anderson, et al. 1985. Effect of photoperiod on milk yield and milk fat in commercial dairy herds. J. Dairy Sci. 68:1134-1140.

Growth Hormone (bST) and IGF

Feedstuffs, Sept. 29, 1986

Tucker HA (1994) Lactation and its hormonal control. Ch. 57, In: The Physiology of Reproduction, 2nd edition, Eds. E. Knobil, J. Neill, et al. Raven Press, Ltd., New York. p. 1065.

Other references on BST in dairy cattle:
Gluckman et al., 1987, J. Dairy Sci. 70:442 (review of GH physiology)
Peel and Bauman, 1987, J. Dairy Sci. 70: 474 (review of BST)
Marsh et al., 1988, J. Dairy Sci. 71:2944 (review of BST)
Bauman, 1992, J. Dairy Sci. 75:3432. (review of BST)
Juskevich and Guyer, 1990, Science 249:875 (BST and consumer saftey)
Klein et al., 1991, Bio/technology 9:869 (BST production by bacteria)
Peel et al., 1981, J. Nutr. 111:1662
Peel et al., 1983, J Dairy Sci. 66:776
Fronk et al., 1983, J Anim. Sci. 57:699
Eppard et al., 1985, J Dairy Sci. 68:1109
Bauman et al., 1985, J. Dairy Sci. 68:1352
Eppard et al., 1985, J Dairy Sci. 68:3047
McCutcheon and Bauman, 1986, J Dairy Sci. 69:38
Cisse et al. 1991, J. Dairy Sci. 74:1370 and 1382
Johnson et al., 1991, J. Dairy Sci. 74:1250
Manalu et al., 1991, J. Nutr. 121:2006
McGuire et al., 1992, J. Nutr. 122:128

*Bauman, D.E. 1992. Bovine somatotropin: review of an emerging animal technology. J. Dairy Sci. 75:3432-3451.

Baumrucker, C.R., and N.E. Erondu. 2000. Insulin-like growth factor (IGF) system in the bovine mammary gland and milk. J. Mammary Gland Biol. and Neopl. 5:53-63.

*Etherton, T.D., and D.E. Bauman. 1998. Biology of somatotropin in growth and lactation of domestic animals. Physiol. Rev. 78:745-761.

Flint, D.J., and C.H. Knight. 1997. Interactions of prolactin and growth hormone (GH) in the regulation of mammary gland function and epithelial cell survival. J. Mam.Gland Biol. Neopl. 2:41-48.

Hoeben, D., C. Burvenich, P.J. Eppard, et al. 1999. Effect of bovine somatotropin on neutrophil functions and clinical symptoms during Streptococcus uberis mastitis. J. Dairy Sci. 82:1465-1481.

Hoeben, D., C. Burvenich, P.J. Eppard, et al. 1999. Effect of recombinant bovine somatotropin on milk production and composition of cows with Streptococcus uberis mastitis. J. Dairy Sci. 82:1671-1683.

Kronfeld, D.S. 2000. Recombinant bovine somatotropin and animal welfare. J. Am. Vet. Med. Assoc. 216:1719-1722.

Lanna, D.P.D., K.L. Houseknecht, D.M. Harris, et al. 1995. Effect of somatotropin treatment on lipogenesis, lipolysis, and related cellular mechanisms in adipose tissue of lactating cows. J. Dairy Sci. 78:1703-1712.

Laurent, F., B. Vignon, D. Coomans, et al. 1992. Influence of bovine somatotropin on the composition and manufacturing properties of milk. J. Dairy Sci. 75:2226-2234.

Shamay, A., N. Cohen, M. Niwa, et al. 1988. Effect of insulin-like growth factor I on deoxyribonucleic acid synthesis and galactopoiesis in bovine undifferentiated and lactating mammary tissue in vitro. Endocrinology 123:804-809.

Tarazon-Herrera, M.A., J.T. Huber, J.E.P. Santos, et al. 2000. Effects of bovine somatotropin on milk yield and composition in Holstein cows in advanced lactation fed low- or high-energy diets. J. Dairy Sci. 83:430-434.

Van Amburgh, M.E., D.M. Galton, D.E. Bauman, et al. 1997. Management and economics of extended calving intervals with use of bovine somatotropin. Livestock Prod. 50:15-28.

White, T.C., K.S. Madden, R.L. Hintz, et al. 1994. Clinical mastitis in cows treated with Sometribove (recombinant bovine somatotropin) and its relationship to milk yield. J. Dairy Sci. 77:2249-2260.

Thyroid Hormones and Deiodinases: in general and in mammary tissue.

Aceves C, Valverde-R C 1989 Type I. 5'-monodeiodinase activity in the lactating mammary gland. Endocrinology 124:2818-2820

Jack LJW, Kahl S, St Germain DL, Capuco AV 1994 Tissue distribution and regulation of 5'-deiodinase processes in lactating rats. J Endocrinology 142:205-215

Kahl S, Bitman J, Capuco AV, Keys JE 1991 Effect of lactational intensity on extrathyroidal 5'-deiodinase activity in rats. J Dairy Sci 74:811-818

Kahl S, Capuco AV, Bitman J 1987 Serum concentrations of thyroid hormones and extrathyroidal thyroxine-5'-monodeiodinase activity during lactation in the rat. Proc Soc Exper Biol Med 184:144-150

Lasren PR, Berry MJ 1995 Nutritional and hormonal regulation of thyroid hormone deiodinases. Annu Rev Nutr 15:323-352

Pezzi C, Accorsi PA, Vigo D, Govoni N, Gaiani R 2003 5'-Deiodinase activity and circulating thyronines in lactating cows. J Dairy Sci 86:152-158

Slebodzinski AB, Brzeinska- Slebodzinska E, Styczynska E, Szejnoga M 1999 Presence of thyroid deiodinases in mammary gland: possible modulation of the enzyme-deiodinating activity by somatotropin. Dom Anim Endocrinol 17:161-169

St Germain, DL 1994 Iodothyonine deiodinases. Trends Endocrinol Metab 5:36-42

St Germain, DL 1997 The deiodinase famly of selenoproteins. Thyroid 7:655-668

Valverde-R C, Aceves C 1989 Circulating thyronines and peripheral monodeiodination in lactating rats. Endocrinology 124:1340-1344

Ovarian Steriods and Pregnancy

Athie F, Bachman KC, Head HH, Hayen MJ, Wilcox CJ 1996 Estrogen administration at final milk removal accelerates involution of bovine mammary gland. J. Dairy Sci. 79:220-226.

Bachman KC 1982. Effect of exogenous estradiol and progesterone upon lipase activity and spontaneous lipolysis in bovine milk. J. Dairy Sci. 65:907-914.

Bachman KC, Hayen MJ, Morse D, Wilcox CJ 1988. Effect of pregnancy, milk yield, and somatic cell count on bovine milk fat hydrolysis. J. Dairy Sci. 71:925-931.

Robertson HA, King GJ 1979. Conjugated and unconjugated oestrogens in fetal and maternal fluids of the cow throughout pregnancy. J. Reprod. Fert. 55:463-470.

Wilcox CJ, Pfau KO, Mather RE, Bartlett JW 1959. Genbetic and environmental influences upon solids-not-fat content of cow’s milk. J. Dairy Sci. 42:1132-1146.

Role of Milk removal

Algers, B., Madej, A., Rojanasthien, S., Uvas-Moberg, K., 1991. Quantitative relationships between suckling-induced teat stimulation and the release of prolactin, gastrin, somatostatin, insulin, glucagon and vasoactive intestinal polypeptide in sows. Vet. Res. Commun. 15, 395-407.

Auldist, D.E., Carlson, D., Morrish, L., Wakeford, C., King, R.H., 1995. Effect of increased suckling frequency on mammary development and milk yield of sows. In: Hennessy, D.P., Cranwell, P.D.. (Eds.), Manipulating Piglet Production V. Proc. Australasian Pig Science Association, p. 137.

Bevers, M.M., Willemse, A.H., Kruip, T.A.M., 1978. Plasma prolactin levels in the sow during lactation and the postweaning period as measured by radioimmunoassay. Biol. Reprod. 19, 628-634.

rooks, P.H., Burke, J., 1998. Behaviour of sows and piglets during lactation. In: Verstegen, M.W.A., Moughan, P.J., Scharma, J.W. (Eds.), The Lactating Sow. Wageningen Press, Wageningen, pp. 301-338.

Fraser, D., 1990. Behavioural perspectives on piglet survival. In: Cole, D.J.A, Foxcroft, G.R., Weir, B.J. (Eds.), Control of Pig Reproduction III. J. Reprod. Fert Ltd., Essex, U.K., pp. 355-370.

Hartmann, P.E., Smith, N.A., Thompson, M.J., Wakeford, C.M., Arthur, P.G., 1997. The lactation cycle in the sow: physiological and management contradictions. Livestock Prod. Sci. 50, 75-87.

Henderson, A.J., Blatchford, D.R., Peaker, M., 1985. The effects of long-term thrice-daily milking on milk secretion in the goat: evidence for mammary growth. Quart. J. Exp. Physiol. 70, 557-565.

Kendall, J.Z., Richards, G.E., Shih, L.N., 1983. Effect of haloperidol, suckling, oxytocin and hand milking on plasma relaxin and prolactin concentrations in cyclic and lactating piglets. J. Reprod. Fert. 69, 271-277.

King, R.H., 2000. Factors that influence milk production in well-fed sows. J. Anim. Sci. 78(Suppl. 3), 19-25.

Knight, C.H., Peaker, M., Wilde, C.J., 1998. Local control of mammary development and function. Rev. Reprod. 3, 104-112.

Pluske, J.R., Dong, G.Z., 1998. Factors influencing the utilisation of colostrum and milk. In: Verstegen, M.W.A., Moughan, P.J., Scharma, J.W. (Eds.), The Lactating Sow. Wageningen Press, Wageningen, pp. 45-70.

Sauber, T.E., Stahly, T.H., Ewan, R.C., Williams, N.H., 1994. Maximum lactational capacity of sows with a high and low genetic capacity for lean tissue growth. J. Anim. Sci. 72(Suppl. 1), 364.

Spinka, M., Illmann, G., Algers, B., Stetkova, Z., 1997. The role of nursing frequency in milk production in domestic piglets. J. Anim. Sci. 75, 1223-1228.

Spinka, M., Illmann, G., Stetkova, Z., Krejci, P., Tomanek, M., Sedlak, L., Lidicky, J., 1999. Prolactin and insulin levels in lactating sows in relating to nursing frequency. Dom. Anim. Endocrinol. 17, 53-64.

Wilde, C.J., Addey, C.V.P., Boddy, L.M., Peaker, M., 1995. Autocrine regulation of milk secretion by a protein in milk. Biochem. J. 305, 51-58.

Wilde, C.J., Henderson, A.J., Knight, C.H., Blatchford, D.R., Faulkner, A., Vernon, R.G., 1987. Effects of long-term thrice-daily milking on mammary enzyme activity, cell population and milk yield in the goat. J. Anim. Sci. 64, 533-539.

Wilde, C.J., Knight, C.H., 1989. Metabolic adaptations in mammary gland during the declining phase of lactation. J. Dairy Sci. 72, 1679-1692.

Rate of Milk Secretion

Elliott, G.M., F.H. Dodd, and P.J. Brumby. 1960. Variations in the rate of milk secretion in milking intervals of 2-24 hours. J. Dairy Res. 27:293-308.

Hamann, J., and F.H. Dodd. 1992. Milking Routines in Bramley AJ, FH Dodd, GA Mein, and JA Bramley, ed. Machine Milking and Lactation, pp. 69-96.

Wheelock, J.V., J.A.F. Rook, F.H. Dodd, et al. 1966. The effect of varying the interval between milkings on milk secretion. J. Dairy Res. 33:161-176.

Milking Frequency

Amos, H.E., T. Kiser, and M. Loewenstein. 1985. Influence of milking frequency on productive and reproductive efficiencies of dairy cows. J. Dairy Sci. 68:732-739.

DePeters, E.J., N.E. Smith, and J. Acedo-Rico. 1985. Three or two times daily milking of older cows and first lactation cows for entire lactations. J. Dairy Sci. 68:123-132.

Erdman, R.A., and M. Varner. 1995. Fixed yield responses to increased milking frequency. J. Dairy Sci. 78:1199-1203.

Gisi, D.D., E.J. DePeters, and C.L. Pelissier. 1986. Three times daily milking of cows in California dairy herds. J. Dairy Sci. 69:863-868.

Henderson, A.J., D.R. Blatchford, and M. Peaker. 1985. The effects of long-term thrice daily milking on milk secretion in the goat: evidence for mammary growth. Q. J. Exp. Physiol. 70:557-565.

Hillerton, J.E., C.H. Knight, A. Turvey, et al. 1990. Milk yield and mammary function in dairy cows milked four times daily. J. Dairy Res. 57:285-294.

Klei, L.R., J.M. Lynch, D.M. Barbano, et al. 1997. Influence of milking three times a day on milk quality. J. Dairy Sci. 80:427-436.

Waterman, D.F., R.J. Harmon, R.W. Hemken, et al. 1983. Milking frequency as related to udder health and milk production. J. Dairy Sci. 66:253-258.

Wilde, C.J., A.J. Henderson, C.H. Knight, et al. 1987. Effects of long-term thrice-daily milking on mammary enzyme activity, cell population and milk yield in the goat. J. Anim. Sci. 64:533-539.

Combined Galactogogues

Dunlap, T.F., R.A. Kohn, G.E. Dahl, et al. 2000. The impact of somatotropin, milking frequency, and photoperiod on dairy farm nutrient flows. J. Dairy Sci. 83:968-976.

Knight, C.H. 1992. Milk yield responses to sequential treatments with recombinant bovine somatotrophin and frequent milking in lactating goats. J. Dairy Res. 59:115-122.

Knight, C.H., P.A. Fowler, and C.J. Wilde. 1990. Galactopoietic and mammogenic effects of long-term treatment with bovine growth hormone and thrice daily milking in goats. J. Endocrin. 127;129-138.

Knight, C.H., J.E. Hillerton, M.A. Kerr et al. 1992. Separate and additive stimulation of bovine milk yield by the local and systemic galactopoietic stimuli of frequent milking and growth hormone. J. Dairy Res. 59:243-252.

Miller, A.R.E., E.P. Stanisiewski, R.A. Erdman, et al. 1999. Effects of long daily photoperiod and bovine somatotropin (Trobest) on milk yield in cows. J. Dairy Sci. 82:1716-1722.

Speicher, J.A., H.A. Tucker, R.W. Ashley, et al. 1994. Production responses of cows to recombinantly derived bovine somatotropin and to frequency of milking. J. Dairy Sci. 77:2509-2517.

Milk Ejection and Oxytocin

For further reading see symposium in J. Dairy Sci. (1983) 66:2226, 2236, and 2251; and Annals New York Acad. Sci., 1992, Vol. 652, Oxytocin in Maternal, Sexual, and Social behaviour.]

Allen, J.C. 1990. Milk synthesis and secretion rates in cows with milk composition changed by oxytocin. J. Dairy Sci. 73:975-984.

Bruckmaier, R.M., and J.W. Blum. 1996. Simultaneous recording of oxytocin release, milk ejection and milk flow during milking of dairy cows with and without prestimulation. J. Dairy Res. 63:201-208.

*Bruckmaier, R.M., and J.W. Blum. 1998. Oxytocin release and milk removal in ruminants. J. Dairy Sci. 81:939-949.

Eicher, S., S. Stewart, D. Reid, et al. 2000. New tools for measuring the effect of stimulation and take-off on milk flows. Proc. Natl. Mastitis Counc. 39;127-133.

Gorewit, R.C., and K.B. Gassman. 1985. Effects of udder stimulation on milking dynamics and oxytocin release. J. Dairy Sci. 68:1813-1818.

Johnson, A.P. 2000. A proper milking routine: the key to quality milk. Proc. Natl. Mastitis Counc. 39;123-126.

Mayer, H., D. Schams, H. Worstorff, et al. 1984. Secretion of oxytocin and milk removal as affected by milking cows with and without manual stimulation. Endocrinology 103:355-361.

Lactation Resources